This car isn't kidding. The dramatic new shape speaks of a shift in direction for the XJ nameplate; the driving experience follows up on the promise. It's true that the previous XJ had an aluminum body and roughly the same chassis architecture, so you could argue this is little more than a reskin and a repowering. But in the first few yards, you realize it represents a comprehensive rethink of what a large Jaguar luxury sedan should be.

It's shifting away from the S-Class or A8 or 7 Series. The XJ feels distinctly sportier. The ride is no longer the waft it was with the old XJ. The V-8 isn't intended to be silent. The steering is quick, the cornering agile. The design isn't meant to communicate formality or businesslike status: It's about panache and extroversion and a bit of fun. Just look at that interior. The most stylish cabin in the world today? I wouldn't disagree.And as to the exterior: Well, as we drive through Paris, a city where people know about style, they stop and point and stare in amazement. Driving through the countryside north of that great city, where the traffic-free rural roads roads are alternately open and sweeping or twisty and bumpy, your reporter is continually amazed too-at the numbers being passed by the speedometer needle.

That is the achievement of the new XJ. Other big sedans use a wider array of active chassis technologies than the Jaguar does; it does without 4WD or 4WS or active steering or active anti-roll. But when the others hunker into their sport modes, they tend to lose fluency. They take every opportunity to remind you what a task it is to make an elephant dance. The XJ is different. It feels remarkably unflustered and natural.
It turns into curves with something approaching glee and stays remarkably flat both in roll and pitch.
The steering is so progressive your confidence rapidly builds. Mid-corner bumps do nothing to upset the action. The deeply contoured seat communicates the car's surprisingly neutral balance. The adaptive dampers are so good they disguise their presence. Most traces of untoward waveforms, whether high-frequency wheelhop or low-frequency body float, are diminished to the point you just don't think about them. Jaguar engineers opted for coil springs at the front (the predecessor was air) for a more natural feel. For the same reason, they bolted the subframe to the body without bushings, though noise refinement is still first rate. At the back, air springs are retained to level the car when laden.

Have we gotten used to an exterior design that aroused initial controversy? Yes, in traffic it looks striking from all angles, novel from some, and beautiful from most -- and athletic, despite its size. Indeed, the increased front track over the outgoing car happened mainly because the designers wanted it. The chassis guys were happy, since it bestowed more grip and less roll. The body engineers had the smarts to deliver a bigger car with greater stiffness but no extra weight.

We're driving a long-wheelbase version, on 20-inch wheels. Under the hood is the 5.0-liter, 385-horsepower engine introduced to the XF and XJ last year. It has variable cam phasing and direct injection, and is a delightfully torquey unit, marked by a soft woofle under light throttle. Light throttle is all you need most of the time, thanks to the combination of that torque, good transmission programming and light vehicle weight. Take it into the upper registers and it still sounds unstressed, but performance is mighty effective. There's a supercharged version above that, available with 470 horsepower-or 510 if you're in a big hurry. A 0-to-60-in-4.7 kind of hurry.

That transmission is operated by the JaguarDrive selector, a drum that powers upward from a flush position on the console. The shifts on the ZF six-speed transmission arrive smoothly just when you need them, making Mercedes' seven-speeder feel fussy. In sport auto mode, it's superb at predicting when you'd want a downshift on entry to a curve. Use the paddles to manually shift under power, and there can be a bit of a thump in the back, but the compensation is a very prompt reward to your demand.

The headline driver-facing technology is a large virtual instrument cluster; except for the clock, there are no actual dials. The thin-film-technology screen imparts information when needed. For example, the area occupied by fuel and temp gauges gives way to a satnav junction diagram as you approach a turn, and a large gear indicator appears in place of the hi-fi selection when you're in manual mode, and the rev-counter will switch to a large active cruise display or car setup configurator as needed.

But otherwise, Jaguar hasn't gone mad with high tech. Perhaps that's a reflection of the firm's relatively small size, but it also matches the XJ's character. There's no night vision, no lane-keeping assist, no follow-to-stop cruise control or autonomous braking.
No, the XJ isn't about fading into the background, transporting corporate bigwigs with their minds elsewhere. It's about the joy of the road. For that reason, Jaguar no longer provides the softest ride in the class. The XJ is never harsh, and when a bump is past it's immediately damped into history. But when you're in the car, you do know there's an actual road beneath. The idea is, you go out there and exploit it.